The present invention relates to telescopic seating systems of the type which are used in auditoriums or gymnasiums and which may be moved between an extended or use position in which the rows are in stepped relation, and a retracted or storage position in which the rows are substantially vertically aligned. More particularly, the present invention relates to a power driven system for moving the rows between the extended and the retracted positions.
One type of apparatus used commercially to drive telescopic seating systems of this type is disclosed in the co-owned U.S. Pat. No. 3,738,612 of Hartman. In this type of apparatus, a motor is mounted beneath the rows in a fixed position toward the rear (for a rear folding system), and it is designed to drive a spool about which a chain is wrapped. A rear folding seating system is one in which the rear or highest row is fixed and the lowest row is moved toward the rear during folding. A forward folding system is one in which the lowermost row is fixed and the highest row is moved forward during folding. The chain is comprised of individual sections designed so as to break in one direction for wrapping around the spool, but not to brake in the other direction, and each section is equipped with wheels, the forward section being connected to the lowermost row. When the spool is driven in one direction, the chain is unwound and extends forwardly, thereby extending the seating system, with the individual links moving along the floor and supported by the wheels. When the spool is driven in the other direction, the chain is wrapped about the spool, and pulls the seating system to the retracted position.
Another type of power folding apparatus is disclosed in U.S. Pat. No. 3,052,929 of Busse, granted Sept. 11, 1962. This apparatus includes a power actuator including a driven wheel positioned behind, but moving with and powering the lowermost row in the case of a rear folding seating system. It includes a number of relatively heavy weights to insure traction between the wheels and the floor, and the diameter of the drive wheels is large enough that they cannot fit beneath the deck of the lowermost row.